Abstract

They had to be, because they were the creations of a perfect God, and a circle is the most perfect of geometrical objects. When Johannes Kepler, after spending most of his career trying to make sense of the meticulous planetary observations of Tycho Brahe, concluded that the orbits of the planets were not circles but ellipses, the discovery sent shock waves through the community of natural philosophers. The discovery led Newton and others to arrive at the inverse square law of gravitational attraction